* {
    padding: 0;
    margin: 0;
}
html , body{
    height: 100%;
    overflow: hidden;
}
.header {
    height: 70px;
    background-color: #354457;
    line-height: 70px;
}
.header .logo {
    width: 200px;
    color: #b3bcc5;
    font-size: 14px;
    margin-left: 20px;
}
.header .logo img {
    width: 30px;
    height: 30px;
    vertical-align: middle;
}
.menu {
    width: 200px;
    height: calc(100% - 70px);
    background-color: #4d5e70;
    color: #b3bcc5;
    font-size: 14px;
    line-height: 40px;
    float: left;
}
.menu dl dt {
    padding-left: 8px;
}
.menu dl dd {
    padding-left: 30px;
    cursor: pointer;
}
.menu dl dd:hover {
    color: #354457;
    background-color: rgba(255, 255, 255, 0.5);
}
.menu dl dd.active {
    background-color: #ddd;
    color: #354457;
}
.content {
    /* calc() 用来计算不同的单位值
     */
    width: calc(100% - 200px);
    height:  calc(100% - 70px);
    float: left;
    background-color: #eee;
    position: relative;
}
.content > div {
    display: none;
    position: absolute;
    width: 100%;
    height: 100%;
}
.content div.content-active {
    display: block;
}
.content form {
    width: 450px;
    margin: 100px auto;
}
form label {
    width: 100px;
    text-align: right;
    display: inline-block;
    margin-right: 10px;
}
form label.sex {
    width: 20px;
}
form > div {
    margin: 10px;
}
#student-add-form .btn {
    padding: 5px 25px;
}
#student-list table {
    width: 100%;
    text-align: center;
    line-height: 30px;
    font-size: 14px;
}
#student-list table thead {
    background-color: #e3e8ee;
    color: #646987;
}
#student-list table tbody {
    background-color: #fff;
}

#student-list table .btn {
    border: none;
    outline: none;
    padding: 3px 10px;
    color: #fff;
}
#student-list table .btn.edit {
    background-color: #5cb85c;
}
#student-list table .btn.delete {
    background-color: #d9534f;
}
.modal {
    display: none;
    position: fixed;
    right: 0;
    left: 0;
    top: 0;
    bottom: 0;
}
.modal-content {
    position: absolute;
    left: 50%;
    top: 50%;
    margin-left: -250px;
    margin-top: -225px;
    width: 500px;
    height: 450px;
    background-color: #fff;
}
.mask {
    position: fixed;
    left: 0;
    top: 0;
    bottom: 0;
    right: 0;
    background-color: rgba(0, 0, 0, 0.5);
}
.content h3 {
    padding: 16px 30px;
}
#student-edit-form {
    margin-top: 0;;
}

.content #student-list {
    display: block;
}
.search {
    padding: 10px 5px;
}
.search #search-inp {
    border: none;
    outline: none;
    font-size: 16px;
}
.search #search-btn {
    background-color: #4d5e70;
    color: #fff;
    padding: 5px 10px;
    border: none;
    outline: none;
    cursor: pointer;
}